Comp SCI 1250 - Homework and Quizzes - Chapter 4-6
This operator takes an operand and reverses its truth or falsehood.
!
This operator represents the logical AND.
&&
When a relational expression is false, it has the value ________.
0
What is assigned to the variable a given the statement below with the following assumptions: x = 10, y = 7, and z, a, and b are all int variables.a = x >= y;
1
For an if statement to conditionally execute a group of statements, the statements must be enclosed in a set of .
Brackets{}
Why should a program close a file when it's finished using it?
Closing the file after using it allows fewer machine resources to be used, and allows otherprograms to access and edit the file.
Either a function's or its must precede all calls to the function.
Definition, prototype
The scope of a variable declared in a for loop's initialization expression always extends beyond the body of the loop.
False
Describe the difference between pretest loops and posttest loops
Pretest loops will only be iterated as long as their required expression is true, posttestloops will run at least once and then test to see if their expression is true for subsequentiterations.
If you are writing a function that accepts an argument and you want to make sure the function cannot change the value of the argument, what do you do?
To prevent the function from editing the argument's value, store the argument as aparameter and perform calculations with the parameter. Make sure the parameter is not inreference mode.
An initialization expression may be omitted from the for loop if no initialization is required.
True
Multiple relational expressions cannot be placed into the test condition of a for loop
True
The update expression of a for loop can contain more than one statement, e.g. counter++, total+= sales.
True
Can an if statement test expressions other than relational expressions? Explain.
Yes, an if statement can test any expression if it can be read as true or false.Question 12:FalseQuestion 14:Brackets {}Question 16:default:Question 28:break statement;Question 30:
Reference variables are defined like regular variables, except there is a(n) in front of the name.
ampersand(&)
Input values should always be checked for:
appropriate range, reasonableness division by zero, if division is taking place
In C++ the = operator indicates:
assignment
Without this statement appearing in a switch construct, the program "falls through" all of the statements below the one with the matching case expression.
break
A function is executed when it is:
called
.eof()
checks to see if the file has read the last line or not, ex. while(fileObject.eof() != true) { fileObject >> data; }
.is_open()
checks to see if the file object succesfully opened, returns 1 if opened, returns 0 if not
Assuming dataFile is a file stream object, the statement dataFile.close();
closes a file
In a function header, you must furnish:
data type(s) of the parameters data type of the return value the name of function names of parameter variables
The trailing else in an if/else if statement has a similar purpose as the section of a switch statement.
default
A function ________ contains the statements that make up the function.
definition
It is a good programming practice to ________ your functions by writing comments that describe what they do.
document
Local variables are initialized to zero by default.
false
The if statement regards an expression with the value 0 as .
false
When an if statement is nested in the else part of another statement, as in an if/else if, the only time the inner if is executed is when the expression of the outer if is true.
false
You must furnish an argument with a function call.
false
This is a variable, usually a boolean or an integer, that signals when a condition exists.
flag
To allow file access in a program, you must #include this header file.
fstream
This is a collection of statements that performs a specific task.
function
This is a statement that causes a function to execute.
function call
To read data from a file, you define an object of this data type.
ifstream
The expression following a case statement must be a(n) .
integer constant/literal
Why is it critical that counter variables be properly initialized?
it is important to initialize counter variables properly because it will affect their scope. Ifa counter variable is defined outside of a loop it will have a wider scope, while if it is defined inthe loop expression it will only have a scope within the loop.
Each repetition of a loop is known as a(n) .
iteration
This type of variable is defined inside a function and is not accessible outside the function.
local
To write data to a file, you define an object of this data type.
ofstream
A file must be ________ before data can be written to or read from it.
opened
The do-while loop is a ________ loop that is ideal in situations where you always want the loop to iterate at least once.
post-test
When the increment or decrement operator is placed after the operand (or to the operand's right), the operator is being used in mode.
postfix
This statement causes a function to end.
return
The ________ of a variable is limited to the block in which it is declared.
scope
Function prototypes are terminated with a semicolon.
true
Global variables are initialized to zero by default.
true
You may use the exit( ) function to terminate a program, regardless of which control mechanism is executing.
true
You may define a ________ in the initialization expression of a for loop.
variable